Charley, the C9OF indicates it is a small block body, which are the same as Y-Block, only the shaft and gear have been changed.
I don't know if Ford sold these over the counter in the 70's as Y-Block replacements or if the rebuilders use that style body because they're easier to get parts for. They usually have the stamped steel weights. The C9OF's are very easy to convert to Duraspark. The reluctor and pick-up drop right in. You will need a later Duraspark dizzy to rob some parts from. Then mill or saw a slot where the primary lead passes through the side of the housing for the Duraspark harness.
Add a cap adapter and a large Duraspark cap and you have a good poboys solid state distributor. You will need an external box of some sort to fire the coil.
http://ford-y-block.com 20 miles east of San Diego, 20 miles north of Mexico
